When I got the 58 Flying Cloud, there was a valve, stem, and heat shield over the sink/dining table, but the lamp parts were long-gone. The copper line went through the over-sink cabinets, into the wardrobe to the left of the stove, down, then back behind the stove where it t'd into the stove supply line, after the shut-off valve. Getting to this valve requires a contortionist, but do-able.
I installed a Falks lamp at this site, but had to move the supply line down, because of the mounting configuration. The lamp itself has a shutoff valve at its base.